The definitions of both update and upgrade come from Debian, not Ubuntu. If you want those terms changed, you must convince the Debian community (not us).
If Debian changed the definitions tomorrow, we would follow suit.
It's important for everybody to use the same terms so we understand apt-related and deb-related questions and answers properly.
So don't ...
One of the primary confusion points we have right now is with the definitions of the following, and what they mean:
End of Standard Support (EoSS)
Long Term Support (LTS)
Extended Security Maintenance (ESM)
End of Life (EoL)
A while ago, the Community Council raised this with Canonical and we got a definitions page written up on the Wiki (managed by ...